1. Field of the Invention
This invention relates to the dispensing of pharmaceutical preparations. More particularly, the invention relates to a device for actively controlling the pattern in which doses of one or more pharmaceutical preparations are administered to a patient.
2. Description of Background Art
When a physician prescribes medication in a nonhospital setting or when an over-the-counter medication is sold, substantial reliance is placed on the patient to comply with the dosing instructions. Unfortunately, even in the case of acute illness, patient compliance with the prescribed dosing regimen is often casual or negligent. This problem, as it is exhibited even among maximally motivated patients suffering from a disease as serious as glaucoma with associated loss of sight, has recently been discussed by M.A. Kass and associates in two papers appearing in Volume 101 of the AMERICAN JOURNAL OF OPHTHAMOLOGY at pages 515 and 524. These papers pointed out that a substantial fraction of the patients took less than one half their required doses of sight-saving medication, that virtually all of the patients reported that they took all of their doses and that the prescribing physicians were completely unable to accurately identify those patients who were not taking their medication. This failure to properly self-medicate can lead to inaccurate feedback to persons monitoring the patient's progress and misinformation regarding the effectiveness of the drug. Similarly, the dosing regimen initially set is often inflexible and not designed to be easily modified to correspond to changes in the patient's condition.
A number of devices have been proposed heretofore as aids to reliable self-medication. These include:
passive medication containers that segregate medicines according to the times they should be taken (for example, the dispensing packages in which birth control pills are marketed);
medication dispensers that provide clock-actuated alarms (see, for example, U.S. Pat. No. 3,651,984 to Redenbach);
medication dispensers from which the patient can receive medication only within certain time intervals (see, for example: U.S. Pat. Nos. 3,722,739 to Blumberg; 3,762,601 to McLaughlin; and 3,815,780 to Bauer);
medication dispensers designed for general use in therapeutics, lacking specifications peculiar to particular pharmaceuticals (see, for example, U.S. Pat. No. 3,911,856 to Ewing); and
medication dispensers that record the times at which the patient removes medication (see, for example: U.S. Pat. Nos. 4,034,757 to Glover; 4,360,125 to Martindale et al.: 4,419,016 to Zoltan; and 4,504,153 to Schollmeyer et al.).
Other references relating to this general subject include the following: U.S. Pat. Nos. 3,369,697 to Glucksman et al.; 3,395,829 to Cogdell et al.; 3,917,045 to Williams; 3,968,900 to Stambuk; 3,998,356 to Christensen; 4,207,992 to Brown; 4,223,801 to Carlson; 4,258,354 to Carmon et al.; 4,275,384 to Hicks et al.; 4,361,408 to Wirtschafter; 4,367,955 to Ballew; 4,382,688 to Machamer; 4,448,541 to Wirtschafter; 4,473,884 to Behl; 4,483,626 to Noble; 4,490,711 to Johnston; and 4,526,474 to Simon.
These prior art devices are sometimes helpful aids for improving the reliability of self-medication. However, implicit in these devices is the assumption that dosage regimen and patient condition are unchanging. In the reality of everyday therapeutics, however, both the prescription of drugs and the self-administration of drugs are subject to many contingencies, including, but not limited to:
changes in the course or nature of the patient's disease;
changes in the overall reliability with which the patient takes a given medication;
particular circumstances that may arise which will prevent the patient from faithfully following the prescribed regimen (e.g., having no access to water, being preoccupied by other business, having previously exhausted the medication supply, or being in a social situation where self-administration of drugs would be embarrassing);
changes in the patient's physiological mechanisms of drug absorption, metabolism or excretion that necessitate changes in the dosing regimen; and
occurrences of acute nausea or vomiting that preclude the oral self-administration of a particular medication.